SIZE OF THE ASPIRATED AIR FLOW Standard EN 14175-4 § 5.5

Test dell’indice di contenimento cappe chimiche

PRINCIPLE OF THE TEST
Measure the extraction air flow from the hood in order to check the aeraulic characteristics of the installation and provide a comparison element for future checks.

TEST METHOD
By measurement on the duct, impractical, by extrapolation of the input speed multiplied by the open surface (the area in square meters of the surface of the latch open to the required size or to the block).

RESULTS
The results are expressed in m³ / h.

ELECTRIC TESTS

PROVE ELETTRICHE

Tests according to EN 61010.

MEASURE OF THE CONFINEMENT EFFECTIVENESS Standard EN 14175-4 § 5.10

MISURA DELL’EFFICACIA DEL CONFINAMENTO

PRINCIPLE OF THE TEST
Free a tracer gas (SF6 sulfur hexafluoride) inside the opening of the hood up and down with controlled flow. Proceed with sampling the gas into the atmosphere, on several points on the front of the hood, to measure the average concentration of the SF6 gas in that area.
The concentration of the tracer gas indicates the leakage at the level of the opening (containment).

TEST METHOD
The SF6 gas generator is positioned in different positions, such as sampling, according to the useful dimensions of the hood.
During the measurements the up and down must be open to the extent required expressly or up to the mechanical block.
Measure the C0 concentration of SF6 gas in the environment (background noise or 0). In the absence of the tracer gas, C0 must be less than or equal to 10 ppb. Free the SF6 tracer gas with a flow rate of 2 liters / minute. Measure the concentration for 480 seconds, remove the value obtained for the first 180 seconds for stabilization. The value of the concentration is expressed in the calculated average from the different concentrations measured during the 300 seconds.
Switch off the SF6 tracer gas generator and repeat for the other measuring points.

RESULTS
For each measurement point, calculate the average CI concentration of the SF6 tracer gas for the duration of the measurement.
Correct the CI value of the C0 ambient concentration. According to the parameters required by the nuona UNI 1603496.